A cable ferry (including the terms chain ferry, swing ferry, floating bridge, or punt) is a ferry that is guided (and in many cases propelled) across a river or large body of water by cables connected to both shores. Early cable ferries often used either rope or steelchains, with the latter resulting in the alternate name of chain ferry. Both of these were largely replaced by wire cable by the late 19th century.

There are three types of cable ferry: the reaction ferry, which uses the power of the river to tack across the current; the powered cable ferry, which uses an engine or electric motors (e.g., the Canby Ferry) to wind itself across; and the fast-disappearing hand-operated type, such as the Stratford-upon-Avon Chain Ferry in the UK and the Saugatuck Chain Ferry in Michigan, USA.

Powered cable ferries use powered cogs or drums on board the vessel to pull itself along by the cables. The cables or chains have a considerable amount of slack built into them, in order to sink below the surface as the ferry moves away, allowing other vessels to pass without becoming grounded, snared or trapped. Where a ferry carries both passengers and vehicles the car deck occupies the centre (helping to balance the vessel) and two passenger areas are at the sides, over the tunnels for the chains and the engines. As the ferry cannot steer a ramp is built at both ends, and there is usually a set of controls facing in either direction.

Cable ferries are common where there is little other water-borne traffic that could get snagged in the cable or chains, where the water may be too shallow for other options, or where the river current is too strong to permit the safe crossing of a ferry not attached to the shore. Alignment of the platform at each end of the journey is automatic and, especially for vehicle ferries, safer than a free-moving ferry might be in bad conditions.

A special type are electrically powered overhead-wire ferries like Straussee Ferry, which have an onboard propulsion unit and can float free, but are connected to the overhead wire for power supply, using an electrical cable that slides along the wire as the ferry moves.

Cable ferries have probably been used to cross rivers and similar bodies of water since before recorded history. Examples of ferry routes using this technology date back to the 13th century (Hampton Ferry in England).

Most of the road crossings of the Murray River in South Australia are cable ferries operated by the state government using diesel engines. The platforms at the ends can be moved up or down according to the water level. At one time, cable ferries were a primary means of automobile transportation in New South Wales in Australia. In Tasmania, for a century before 1934, the Risdon Punt at Hobart was the only fixed method of crossing the Derwent River within Hobart city limits.

The earliest punts were privately owned by local landowners, and charged a toll. As governments started to build roads, they started to build and operate punts as required. Private punts might be bought out, or made to impose more standard tolls.[2]

There are more than 100 cable ferries in the Netherlands,[19] 11 of which use a floating cable with a single anchorage. The larger ones are usually powered by a diesel-powered screw propellor, the smaller ones often use the cable for propulsion. Most of the larger cable ferries angle themselves in the stream to gain part of their propulsion from the current, as a reaction ferry.